Five years ago, cheers coming from Northport helped Mikey Brannigan win a gold medal at the Paralympics in Rio.

Now the runner with autism is hoping to hear them again.

The last time Brannigan raced in the Paralympics, he flexed his muscles at the start, and at the finish, he easily won the gold. He has no plans on giving it up.

"My goal and hope is to defend my Paralympic title," Brannigan said. "I believe I can."

But Brannigan is not the same guy who blew away the field five years ago in Rio. He was a 5-foot-9-inch teenager back then. Now he's all grown up and stands at 6 feet, 1 inch tall.

"That was his biggest thing for the last couple of years, his growth spurts, where his body was just like coming out of itself in a way and he finally settled las year," said his father, Kevin Brannigan.

His parents said Brannigan had growing pains and doctors told them to cut back on his training.

His coach, Sonya Robinson, said Brannigan is still getting used to his height.

"Everyone once in a while he'll trip over himself and I'm like, 'Oh My God! Please don't grow again. I thought you were done,'" Robinson said.

Brannigan is the first runner with autism to break four minutes in the mile. That was five years ago and so with that added height and muscle Brannigan said he is determined to run faster.

"We are so excited to watch him run on the world stage again. But I can tell you when I watch him run, I watch like this," said his mother, Edie Brannigan, as she covered her eyes with her hands, but peaking between her fingers.

"Now when we see him run sometimes, when he's in the races he's in, I can't really pick him out anymore. He's like the regular professionals," said Kevin Brannigan.

Brannigan could be easy to spot after his next race as he could be the one with another gold medal.